Magneto-dynamo armature.



R. H. CUNNINGHAM. MAGNETO DYNAMO ARMATURE.

APPLIOATIONZYILED DEC, 30, 1909.

Patented Mar..7, 1911.

M/Vf/VTOR Br z WITNESSES:

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lTTO/ME Y RICHARD H. CUNNINGHAM, 0F NEW YORIQFN. Y.

MAGNE'romYnAMo ARMATURE.

Specification of Letters latent.

Patented Mar. 7, 1911.-

, application filed December 30. 1909. Serial 1535.635.

To all whom it mayconcern:

Be it known that I, Riclunn I-L'Ccxxrxonan, a citizen of the United States, residing at the city of Xew York, in the borough of Manhattan and State of New York. have invented certain new and useful Improvements in Magneto-Dynamo [Dana-titres, of which the following is a full, clear, and exact description.

This invention relates to H-armatures for high-tension magnetos, and particularly to a variety oi' features of improvement in the construction thereof. The use of these machines, having the so-called H or shaped armature, is now standardpractic in ignition systems, but difficulties are found in matters of insulation. and in making the construction reliable and free" from possihility of. any mechanical loosening, breakage or change of adjustment. These matters 'are particularly serious in the use of a. magneto generator in motor vehicles for the reason that any defect in the magneto works great discomfort because the magneto by its nature is not susceptible to temporary repair. It is universally recognized tlnit the magneto should be especially reliable in the automobile equipment. 'Xe'verthcless the magnetois subjected to severe mechanical conditions. including shocks and vibration and is driven at high and varying speeds. Electrically considered, its insulating parts are called upon to withstand potentials of 2000 volts and over. It has been the practice to make the mechanical construction and the insulation of magneto armatures with elaborate and painstaking care, but this care has rendered the first cost high and the repairs correspondingly expensive.

The main object of my invention is to so improve the various features of construction of a magneto; H-shaped armature throughout as torender itas proof as possible against breakage or failurctrom any cause, and further to providea construction of such a nature that the elaborate care hitherto necessary is not so particularly required. And correspondingly itis a purpose of my invention to renderreparrs of the armature easy and inexpensive to make, if under any circumstances such repairs should become. necessary.

More specifi ally stated, I aim to improve the construction of the H-shapcd core so as to rcnder the winding and assembling of manner.

the coil thereon easilyaccomplished, but without increasing the magnetic leakage or diminishing the etticiency of the magnetic circuit. Further I provide for insulating the windings and particularly the high potential-portion of the secondary winding in a very simple manner. but with an etliciency as high as is possible in view of the nature of the conditions. Furtl1er I provide a means for leading out the'primary and secondary terminals sothat the wires will not be broken This last is a most important source of failure that must be guarded against, because the wirescarrying current as they do in a continuously varying magnetic field, are subjected to bending forces back and forth which are liable to rupture these conductors unless their anchorages are made particularly secure. In prior constructions this has been accomplished by running the conductors through ducts in the solid core in some cases; I obtain as great'efiiciency, in a .simpler and cheaper Furthermore I lead the primary and secondary terminals to the collector br'ushesor contacts of the outside circuits, through the tubular shaft of the armature by -a construction which may be considered as absolutely proof against.- failure from any cause. I further provide a simplified form of end plates or heads for the armature core and generally facilitate the construction and particularly the. assemblingof the complete device. V

In the drawings: Figure 1 is a side clevation of the armature with the end plate 16 removed; 'Fig. 5 illustrates a modification.

Referring to thedrawings, l-denotes an H or H-ishaped core for the armature of a high tension magneto, The core essentially comprises two segmental portions 2 joined together by a connectin' web 3 which the coils -areafterward ma 0 to surround, the segmental portions 2 acting asheads at the ends of the coils or windings. As in prior constructions,- I prefer to make the core of cast iron with laininations extending transverscly across the same these lammations thus extending through and forming the majorpart {of the web '3. The distinctive feature of novelty in my core, and which so far asv I anraware is. new in this class of '1YlfiChl I18,' is the'dividing of the web 3 in a plane between the segemental portions 2, the two juxtaposed faces of the thus divided web being carefully finished or machined. As will later appear these faces are' pressed tightly together when the core is assembled sothat the magnetic circuit is not impaired or the magnetic leakage increased.

Instead of these plane faces, the web may be machined on a zig-zag or splice-joint path it desired as shown in Fig. 5. The primary and secondary, windings are denoted 4 and 5 and are preferably machine wound in a lathe or winding machine so that in their -completed form they may be fitted together located between the ends of the coils and the adjacent fiat faces of the segmental portions 2 of the core.

9 denotes an' insulating wrapping on the outsideof the secondary 5. 'These insulating wrappings separate all parts of difierent potential-from one another, but I provide special means, constituting an' important part of my. invention, to insulate the high potential portions of the secondary, z'. e. those portions which have voltages of 10,000 or 20,000 volts, and by virtue of which the insulation is alone subjected to any considerable dielectric stress.

10.denote formed cupsof hard rubber or insulating material, perforated to closely receive the tube or shell 7 which covers the primary winding, and adapted to fit over are of round, oval or oblong shape, corre-' sponding to the form of the secondary. and slide or fit closely over the peripheral surface of the latter so as to leave only a narrow central band or zone 12 of said secondary winding uncovered. At this particular zone the winding is, of course, protected by the wrapping 9 which is applied spirally'and' lapped (see Fig. 4) 'to permit the exit of the high potential secondary terminal. The lattor is closely inclosed in a hard fiibber tube 13 inserted between the ends of the wrapping 9 at the point of issuance of said terminal so as to prevent it from working or bending under theelectrical forces set up, in the manner already referred to. Inasmuch as the potential in the secondary increases from zero at its inner layers to a maximum at its outer layers, it is evidentthat'dielectric stresses to cause a spark can only be exerted 'either directly through the material of the cups 10 or along the entire inner surface thereof, in addition to traversing or passing around'the insulating shell 7 and plates 8. The central zone 12 of the secondary winding is separated by a considerable gap from the end plates 15, 16 of the armature, and by its nature also from the poles of the field magnet, and is furtherjpro- .tected by the insulating wrapping 9, so that no liability to break down at this point need be feared.

It will be observed that everything thus far described, even including the windings. is capable of being made, formed or stamped out cheaply, and furthermore is adapted to .be quickly assembled.

As an important part ofthe characteristics permitting the foregoing advantages,it is to be noted that the terminals of the primary winding are received in grooves ofth'e core by the mereassembling or positioning of the parts ofithe latter, but are nevertheless anchored with the greatest possible firmness in subsequent use. A groove 35, is

formed on the internal face of each segmental portion 2, the grooves extending parallel to the axis of the armature and located opposite thepoints of exit of the terminals at the ends of the primer; coil. In this way the two primary terminals are brought to one end of the armature on diametrically opposite outer portions thereof, and the sec-- ondary terminal is likewise brought to this same end of the armature at the middle in the manner already described. The inner end of the secondary is grounded on the primary terminal adjacent-thereto the latter being located in its appropriate groove at this point.

15, 10 denote the end plates of the arma ture which I make of simple form or construction, being merely metallic disks with permanently associated stub-shafts l7, l8, projecting therefrom. The stub-shaft 18 is hollow and is tightly fitted with three in terior concentric sleeves 19, 20 and idiot insulation, steel or metal, and again insulation, successively. At the center there is tightly fitted a stcelor conducting rod 22.

The two insulating sleeves 1!), 21 are both flanged'or presided with equivalent insulating washers 19, 21 at their inner ends.

-The steel or conducting tube 20 is also flanged, this flange '20 being located hetween the insulating flanges i9, 21. One primary terminal is connected to this flange from any low potential metal part.

to where it has a head 26to which the secondary terminal is soldered. At its other end this rod has a cap or head 27 which is separated from the nearest adjacent metal by an insulating bushing 28 which is slipped 1 5 on the insulating sleeve21.

I 30 denotes a conducting ring screwed on the steel or conducting tube at the inner end of the insulating bushing 28; This metallic ring is separated from the metal of '20 the stubshaft 18 by an insulating ring 31 fitted on the end of the insulating sleeve.

By the foregoing construction the hollow.

stub-shaft 18 is made substantially as strong as if itwere integrally sol d, and the pminary and secondary terminals are led out by a. construction which may be considered as practically proof against failure either me.- chanically or electrically. The cap 27 forms the secondary terminal and is widely separated from any grounded metal part. The

ring 30 is adapted to be engaged by a brush of any suitable construction to efficiently completethe primary circuit. Vithin the armature the primary terminals are separated at every pointfrom any adjacent metal and are so confined as not to be vibrated or broken in use. The secondary terminal is completely inclosed and widely separated by both air gap and insulation The two sect-ions of the core are held together by the end plates 15, 16 which are rimmed and screwed thereon in the usual manner not necessary to be described.

It. is believed that the foregoing armature realizes all the-advantages pointed out 111 the preliminary part of this specification, but is adapted to be simply constructed and assembled without the extraordinary painstaking care generally necessary in these constructions, Having described my invention, I claim:

.1. In a high tension armature for a magneto dynamo an H-shaped eorehaving'two segmental portions joined by a connecting web, said web being divided between said segmental portions.

9. In a high tension armature tor a magneto dynamo, an 'H-shapcd core having two t0 segmental portions joined by a connecting web. said'web being divided midway between said segmental portions.

3. In a high tension armature for a magneto. dynamo, an H-shaped core having two 6.3 segn'lental portions joined by a connecting web, said web being divided with two juxtad machined faces transverse thereto and midway between said segmental portions, as and for the purpose set forth. 1 4:. In a high tension armature for a magneto dynamo, an H-shapedco're having two segmental portions joined by a connectmg 1 web, a solid non-magnetic end plate, a tubularsha-ft fixed to said end plate, a conducting tube tightly hushed in said shaft, a con- .primary winding having a terminal connected to said tube and a secondary ing having a wrapping with a lapped outside end, and a terminal extending under the lapped portion of said wra ping, said terminal being joined to-said r 5. In a high tension armature for a magnetodyna mo, an H-shaped core, a primary winding received on said core and having central and peripheral :tubular insulating shells, a secondary winding shorter than said primary, formed insulating cups fitting over the ends of said secondary and filling out the length thereof to equal the length of the primary, and a wrapping on said secondary exposed in 'a' zonebetw'een said cups and under the lapped outer extremity of which the secondary high potential terminal is led.

6. In a high tension. armature for a magneto dynamo, an H-shaped core having two segmental portions joined by a connecting web, said web being divided between said segmental portions, associated primary and secondary windings, and formed insulating cupsfitting over the ends of the secondary to separate the latter from the adjacentfaces of the core. I

7 In a high tension armature for a magneto dynamo, an H-shaped core having two segmental portions joined by a connecting web, said web being divided between said segmental portions, associated primary and secondary windings insulated-from one another and from said web and from the segmental-portions of said core, and formed, insulating cups fitting over the ends of the secondary and separating the same from the segmental pbrtlons of the core, said cups approaching one another to leave a narrow exposed band of said secondary midway be tween the segmental portions of the core.

' 8. In a high tension armatur for'a magneto dynamo, an H-shaped core} having two segmental portions joined by a connecting web, said web "being divided between said segmental portions, associated primary and secondary windings insulated from-cone another and from said web and from the segmental portions of said core, formed insulating cups fitting over the ends of the secondary and separating the same from the segmental portions of the core, said cups approaching one another to leave a narrow exposed band of said secondary midway ducting rod tiglitly bushed in said tube, a-

wind-' I web, said web being divided between said -a tubular shaft fixed thereto, a conducting tube and a conducting rod within said shaft,

. said sleeves having insulating flanges, a rian insulating chamber.

between thesegmental portions of the core, and a high potential terminal of said secondary led out in said exposed zone between said cups. I I w 9. In a high tension armature for a mag neto dynamo, an H-shaped core,-an end plate,

insulating sleeves separating said rod and tube from one another and from saidshaft,

inary winding'having a terminal joine to said tube between the flanges of said sleeves, and a secondary winding having a terminal joined to-said rod. one of said flanges being formed with an insulating tubular nipple towholly inclose said secondary terminal in 10. In a high tension armature for a magneto dynamo, anH-shaped core having two segmental portions joined by a connecting Segmental portions, and said segmental portions being respectively grooved on an interior flat face, and windings having terminal wires led outwardtherefrom, said wires being received in said grooves when the parts of said core are assembled together.

11. In a high tension armature for a-magneto dynamo, an' H-shaped core, anon-ma netic end plate, a tubular shaft fixed there--' sleeve, a cap on said rod, an insulating bush ing separating said cap flOlILSflld conducting ring, and primary and secondary windings having terminals respectively connected to said tube and rod.

In witness whereof, I subscribe my signature, in the presence of two witnesses.

RICHARD H. CUNNINGHAM.

Witnessesi WALDO M. CHAPIN, WILLIAM C. LANG.

Copies of this patent may be obtained (or five cents each, by Erasing the10omi I 4 r a an Washington; 11, is a -9 

